The mutations are the first evidence that the radiation has caused genetic changes in living organisms. They are likely to add to concerns about potential health risks among humans though there is no evidence of it yet. Scientists say more study is needed to link human health with the Fukushima disaster.

The catastrophic meltdowns in three reactors of Fukushima Dai-ichi power plant after it was damaged by the 9.0-magnitude earthquake and tsunami on March 11, 2011, prompted a public backlash against nuclear power, and forced the government to reassess resource-scarce Japan’s entire energy strategy.

But the most visible example of the radiation’s effect was claimed by a group of Japanese researchers who found radical physical changes in successive generations of a type of butterfly, which they said was caused by radiation exposure. They also said that the threat to humans – a much larger and longer-lived species – remains unclear.

“Our findings suggest that the contaminants are causing ecological damage. I do not know its implication to humans,” Joji Otaki of the University of the Ryukyus in Okinawa, a member of the research team, told The Associated Press in an email.

A separate study, released this week, found very low levels of radioactivity in people who were living near the Fukushima plant when it suffered the meltdowns.

The paper, published in the Journal of the American Medical Association, measured cesium levels in 8,066 adults and 1,432 children and found average doses of less than 1 millisievert, which are considered safe. It was the first such study measuring internal exposures to cesium in a large number of people from the disaster.

The research shows contamination decreased over time, particularly among children, in part because more precautions were taken with their food, water and outdoor activity.

“No case of acute health problems has been reported so far; however, assessments of the long-term effect of radiation requires ongoing monitoring of exposure and the health conditions of the affected communities,” the report said.

AP Photo/Masaki Iwata of University of the Ryukyus In this undated photo taken by Masaki Iwata of Univesrity of the Ryukyus and released by the university, a normal adult pale grass blue butterfly suckles nectar from a flower. Japanese researchers said they found mutations in butterflies caused by radiation from the crippled Fukushima Dai-Ichi nuclear power plant. A member of the team conducting the research, Joji Otaki of the university, said Wednesday, Aug. 15, 2012, that his group's findings show radiation emitted following catastrophic meltdowns in three of the plant’s reactors after it was damaged by a 9.0-magnitude earthquake and tsunami on March 11, 2011 is affecting the environment.

So far, the actual radiation doses inflicted just after the accident are not exactly known, though exposure is thought to be very small, said David J. Brenner, a radiation physicist at Columbia University, who was not part of the research.

“We do need improved estimates of the radiation dose that people in and near Fukushima prefecture actually received,” he told the AP. “Right now our estimates are based on very, very rough calculations.”

The research on the butterflies was published in Scientific Reports, an open-access online journal by the Nature publication group, which provides faster publication and peer review by at least one scientist.

It says pale grass blue butterflies, a common species in Japan, collected from several areas near the Fukushima plant showed signs of genetic mutations, such as dented eyes, malformed legs and antennae, and stunted wings.

Kyodo / Reuters No North American evacuation required: The tsunami-crippled Fukushima Daiichi nuclear power plant's reactor building number 4 is seen in Fukushima prefecture, in this aerial view photo taken by Kyodo on July 5, 2012

Other experts said they viewed the research as significant.

“Scientists have long known that radiation can be hazardous to human and animal health. Studies of this sort at Fukushima and Chernobyl provide invaluable information concerning just how hazardous radioactive contaminants could be for human populations living in these areas in the future,” Tim Mousseau of the University of South Carolina, told the AP by email.

“Butterflies as a group are important bio-indicators for the effects of environmental stressors like radioactive contaminants,” said Mousseau, who also is not part of the Japanese research.

The results show the butterflies were deteriorating both physically and genetically, with the share of those showing abnormalities increasing from 12 percent in the first generation to 18 percent in the second and 34 percent in the third.

To study the genetic changes, the scientists raised the new generations of the butterflies in Okinawa, which has not been affected by the radiation releases, mating each abnormal butterfly with one unaffected by such changes.

The researchers also demonstrated the effects of internal exposure to radiation by feeding leaves from plants from the area near the Fukushima nuclear plant to the butterfly larvae.

“The possible risk of internal exposure from ingestion should be investigated more accurately in the near future,” it said.

Although the damage is irreversible, the species could develop resistance to the radiation, Otaki said. “In that case, we will observe adaptive evolution,” he said.

The research appears to be “a very thorough study,” said Jim T. Smith of Britain’s University of Portsmouth, also another outsider. The replication of the mutations under lab conditions further supports the report’s findings, he said in a telephone interview.

However, he said he would be “very, very wary of trying to extrapolate those results to humans.”

Even in the area near Chernobyl in the Ukraine, the absence of humans who left after the 1986 nuclear accident there has actually benefited local fauna in the long run, said Smith, who has conducted research on radiation’s effects on aquatic insects.

]]>http://news.nationalpost.com/news/radiation-from-japan-nuclear-disaster-results-in-mutant-butterflies/feed5stdIn this undated photo taken by Chiyo Nohara at University of the Ryukyus and released by the university, an adult pale grass blue butterfly collected near the crippled Fukushima Dai-ichi nuclear power plant is shown with dented eyes and stunted wings at the university laboratory in Nishihara, Okinawa, southern Japan. Japanese researchers said they found mutations in butterflies caused by radiation from the power plant. A member of the team conducting the research, Joji Otaki of the university, said Wednesday, Aug. 15, 2012, that his group's findings show radiation emitted following catastrophic meltdowns in three of the plant’s reactors after it was damaged by a 9.0-magnitude earthquake and tsunami on March 11, 2011 is affecting the environment.In this undated photo taken by Masaki Iwata of Univesrity of the Ryukyus and released by the university, a normal adult pale grass blue butterfly suckles nectar from a flower. Japanese researchers said they found mutations in butterflies caused by radiation from the crippled Fukushima Dai-Ichi nuclear power plant. A member of the team conducting the research, Joji Otaki of the university, said Wednesday, Aug. 15, 2012, that his group's findings show radiation emitted following catastrophic meltdowns in three of the plant’s reactors after it was damaged by a 9.0-magnitude earthquake and tsunami on March 11, 2011 is affecting the environment. Tokyo Electric Power Co. (TEPCO)'s tsunami-crippled Fukushima Daiichi nuclear power plant's reactor building number 4 is seen in Fukushima prefecture, in this aerial view photo taken by Kyodo on July 5, 2012. Japan's Fukushima nuclear crisis was a preventable disaster resulting from "collusion" among the government, regulators and the plant operator, an expert panel said on Thursday, wrapping up an inquiry into the worst nuclear accident in 25 years.Japan declares two idle nuclear reactors safe, as country faces power shortageshttp://news.nationalpost.com/news/japan-declares-two-idle-nuclear-reactors-safe-as-country-faces-power-shortages
http://news.nationalpost.com/news/japan-declares-two-idle-nuclear-reactors-safe-as-country-faces-power-shortages#commentsFri, 13 Apr 2012 13:03:58 +0000http://news.nationalpost.com/?p=161603

TOKYO — Two idled Japanese nuclear reactors operated by Kansai Electric Power Co have been declared safe and will need to be restarted, Japanese Trade Minister Yukio Edano said on Friday.

Edano made the comments at a news conference after he, Prime Minister Yoshihiko Noda and two other ministers met to discuss whether to allow the first reactor restart since last year’s Fukushima atomic crisis.

The No.3 and No.4 units at Kansai’s Ohi nuclear plant have cleared the government’s technical review on resilience against a severe event like last March’s massive earthquake and tsunami.

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Before the Fukushima crisis, nuclear met more than 40 percent of power need in Kansai’s service region around Osaka, Japan’s second-biggest metropolitan area and home to the factories of several top electronics makers.

Only one of Japan’s 54 nuclear reactors remains in operation, as public worries over nuclear safety left communities reluctant to approve restarts of reactors taken offline for routine maintenance.

]]>http://news.nationalpost.com/news/japan-declares-two-idle-nuclear-reactors-safe-as-country-faces-power-shortages/feed2stdThis picture taken on April 12, 2012 shows the third (R) and fourth reactor building of the Ohi nuclear power plant of the Kansai Electric Power Co at Ohi town in Fukui prefecture, western Japan.Post Primer: Explosion at Japan’s nuclear planthttp://news.nationalpost.com/news/post-primer-explosion-at-japans-nuclear-plant
http://news.nationalpost.com/news/post-primer-explosion-at-japans-nuclear-plant#respondSat, 12 Mar 2011 17:36:15 +0000http://news.nationalpost.com/?p=52030

Analysts and industry representatives gave different assessments of the potential dangers after an explosion blew the roof off one of Japan’s nuclear power plants damaged in Friday’s massive earthquake.

It underlined the fluid and unpredictable situation at the Fukushima Daiichi facility north of Tokyo, from which the Japanese government said radiation leaked.

The critical issue is what has happened or is happening with the reactor fuel — which contains almost all the radioactivity in the plant — and whether it is damaged.
“We don’t know enough about what the status of the fuel is in the reactor core,” Mark Hibbs of the Carnegie Endowment for International Peace said. “The issue is whether the core is uncovered, whether the fuel is breaking up or being damaged, or whether the fuel is melting.”

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WHAT HAPPENED AT THE PLANT?
The blast at the 40-year-old Daichi 1 reactor came as plant operator Tokyo Electric Power Co (Tepco) 9501.T worked to reduce pressures in the core after the total loss of power needed to keep water circulating to prevent it from overheating.

It led to fears of a disastrous meltdown at the plant, which automatically shut down after the quake, even though the government insisted that radiation levels were low.

“The most probable (cause of the explosion) is the coolant, particularly if it’s water, can overheat and turn to steam more rapidly than it was designed to cope with,” said nuclear fuel technology professor Timothy Abram at Manchester University.

The cause and exact location of the blast still needs to e established, said nuclear physics professor Paddy Regan at the University of Surrey. “So far it looks like it’s not the reactor core that’s affected, which would be good news.”

The World Nuclear Association, a London-based industry body, said the blast was probably due to hydrogen igniting and that this was unlikely to cause a big accident by itself.

“It is obviously an hydrogen explosion,” communications director Ian Hore-Lacy said. “If the hydrogen has ignited, then it is gone, it doesn’t pose any further threat.”

HOW SERIOUS COULD IT BE?
Views differ. Stratfor, a risk consultancy, said the blast appeared to have caused a reactor meltdown, but this was contradicted by others who dismissed any comparisons with the 1986 Chernobyl nuclear disaster in Ukraine.

“The reactor fuel appears to have at least partially melted, and the subsequent explosion has shattered the walls and roof of the containment vessel,” Stratfor said in an analysis.

“There have been reports of “white smoke,” perhaps burning concrete, coming from the scene of the explosion, indicating a containment breach and the almost certain escape of significant amounts of radiation.”

But Abram, the Manchester professor, said it was unlikely it would develop into anything more serious, even though this would depend on the integrity of the fuel.

He believed it would be “pretty unlikely” that the fuel itself had been significantly damaged, but if this had happened, some radioactive material might be released into the plant’s primary circuit.

In comments that appeared to back up this view, Japan’s top government spokesman said the plant’s concrete building collapsed in the blast, but the reactor container inside did not explode.

The spokesman said Tepco, the operator, planned to fill the leaking reactor with sea water to cool it down and reduce pressure.

Carnegie’s Hibbs said: “If they are suggesting that the reactor vessel is intact and that they have a way to get cold water into the core of the reactor to cool that core down, that is very good news indeed.”

]]>http://news.nationalpost.com/news/post-primer-explosion-at-japans-nuclear-plant/feed0stdPeople hug each other in an evacuation center set up in a middle school gymnasium in Rikuzentakata City, Iwate Prefecture in northeastern Japan March 12, 2011. Japan confronted devastation along its northeastern coast on Saturday, with fires raging and parts of some cities under water after a massive earthquake and tsunami that likely killed at least 1,000 people.